A former lab worker, David Kwiatkowski has been charged with stealing drugs from the hospital and replacing them with tainted syringes that were later used on patients. Thirty-two patients have been diagnosed with the same strain of the virus Kwiatkowski carries since the investigation began in May.

Kwiatkowski, whom prosecutors describe as a "serial infector," previously worked in seven other states, and thousands of hospital patients in those states are being tested to see if they, too, were infected with hepatitis C, a sometimes life-threatening virus that can destroy the liver. A handful of patients in Kansas have been diagnosed with the same strain Kwiatkowski carries.

Kwiatkowski, who has told authorities he did not steal or use drugs, has pleaded not guilty to illegally obtaining drugs and tampering with a consumer product.

While federal authorities continue their criminal investigation -- a judge this week agreed to give prosecutors more time to indict Kwiatkowski -- the state Department of Health and Human Services also has been working to define the extent of the outbreak, recommend testing for exposed patients and otherwise protect the public.

But Exeter Hospital has asked a Merrimack County Superior Court judge to prevent the state from further accessing patient records and conducting interviews with staff unless the state is more specific in its requests.

In a motion filed in August, the hospital said it has already provided thousands of pages of medical records and wants to continue to cooperate with the investigation. But it claims the state has requested unfettered access to medical records "regardless of their relevance or importance to the investigation and without regard to the federal and state privacy rights of Exeter's patients."

Associate Attorney General Ann Edwards said the hospital has been less than cooperative.

"It changed in August, and the argument that Exeter Hospital has made is that there are now concerns about the privacy of patients, and they've prevented us from having access to that, and they have also stopped us from being able to interview their staff unless their legal counsel is present, or one of their managers," Edwards said.

Hospital officials said they want the state to write up a list of specific patient records it needs and to identify which portions of those records are necessary to review.

"As stated previously, Exeter Hospital is concerned about the breadth of the state's broad request for access to patient medical records without a clearly articulated argument for why that access is critical to support their investigation," the hospital wrote in a statement.

On Tuesday, the attorney general's office filed an objection to the hospital request and asked for a hearing, saying hospitals are required by law to provide information during a communicable disease investigation.

"Rather than limiting access, state and federal laws expressly provide Public Health access to patient records," the attorney general's office wrote on behalf of the health department.

Edwards said the hospital's objection is limiting the investigation.

"It's really interfering with our ability to be able to ask questions in situations where staff doesn't have to worry about reprisals to the answers they give," she said.

Hospital officials said they are just following the law.

"Exeter Hospital is required by state and federal law to protect our patients' confidential medical records from inappropriate access, even by state officials. We are prepared to support the court's judgment on whether the state's request is in compliance with state and federal privacy laws," officials wrote in a statement.

The Attorney General's Office hopes that the courts will rule on the objection within a few weeks so that it can move on with its investigation.

Kwiatkowski was hired in Exeter in April 2011, and previously worked at 18 hospitals in Arizona, Georgia, Kansas, Maryland, Michigan, New York and Pennsylvania. He moved from hospital to hospital despite having been fired twice over allegations of drug use and theft.